In the process of fabricating windows for automotive vehicles, glass templates are first cut from glass sheets in a desired pattern. These templates are stacked in a container for shipping to a location where they will be processed further. Fabrication of the templates into automobile backlites, e.g., involves removing one template at a time from the container, placing it on a conveyor belt for travel through washing equipment, painting the outer portion with black paint and then shaping the painted template into a final form as by press or sag-bending. The first step, removing the template from the container and placing it on a conveyor belt, is generally handled by means of a robotics arm which has suction cups that attach to the template. Since these glass stacks generally contain multiple pieces of glass, it is critically important that these templates separate easily. Otherwise, instead of only one template being removed from the stack, a group of adherent templates would be lifted out together. Since the suction cups are not able to maintain suction of the group, they would end up as scrap on the floor.
Conventionally, in the glass making industry, to assure that the templates separate easily from each other, a layer of a powdered separating agent is provided over the entire surface of one of the broad template surfaces. One of the drawbacks of providing a coating on the entire glass template surface is that it obstructs the visibility of any defects present in the glass. The result is that glass of less than desirable quality may be inadvertently shipped. It may be that only after the additional investment of cost and time for fabrication is the less than desirable quality apparent. It would be commercially desirable to be able to determine, prior to shipping or processing, which templates are of less than desirable quality to prevent their shipment. The present invention overcomes such disadvantages. We have unexpectedly found that by providing a powdered separating agent in substantially parallel strips across a surface of the glass sheet, i.e., covering only a relatively small portion of the glass surface, easy separation of the glass sheets is attained while at the same time allowing viewing of the glass for defects. In addition to the invention advantages described above, the invention is effective in reducing glass manufacturing costs since substantially less separating powder is used as compared to the prior art separating processes which provide a coating over the entire surface of the glass sheet.